FIGS. 7 and 8 are a cross-sectional view and an exploded view showing a conventional panel switch. The switch has an insulated substrate 2 on which a first contact point la and a second contact point 1b are formed. The reference numeral 3 denotes a spacer having a through hole 3a. The spacer 3 has adhesive layers on opposite sides, and accommodates a spherical or cylindrical resilient metal diaphragm 4. The diaphragm 4 is covered with an elastic sheet 5. The reference numeral 7 denotes a casing which holds a press button 6. The diaphragm 4 keeps contact with the second contact point 1b.
For operation, an operator pushes the press button 6 so that the diaphragm 4 is pressed and comes into contact with the contact point 1a through the sheet 5, thereby effecting electrical connection between the contact points 1a and 1b by way of the diaphragm 4.
This type of panel switch has the following disadvantages:
One is that the spacer 3 is indispensable for maintaining the diaphragm 4 and cannot be omitted. The cost of the spacer is reflected in the production cost. Another disadvantage is that the diaphragm 4 must be individually inserted into the apertures of the spacers 3, thereby consuming time and labor. In addition, the boring of the apertures produces chips, dirt and adhesive remains, which are likely to cause poor contact between the diaphragm 4 and the contact points 1a, 1b.